How is energy conserved in a closed system?

In a closed system, energy conservation is governed by the principle that energy cannot be created or destroyed, but can only be transformed from one form to another. This means that the total amount of energy remains constant within the system, even though it might change its form — such as from kinetic energy to potential energy, or from thermal energy to mechanical energy. This principle underlies many laws of physics, including the law of conservation of energy.

For example, when a ball is thrown into the air, its kinetic energy is converted into potential energy as it rises. When the ball reaches its peak and begins to fall, the potential energy converts back into kinetic energy. Throughout this process, the total energy in the system remains constant, demonstrating energy conservation through transformation rather than destruction or creation.

Understanding this fundamental principle is key in mechanical contexts such as machinery, thermodynamics, and various engineering applications, where energy transformations are critical to predicting system behavior.